This invention relates to sealed watch cases and particularly to a new and improved sealed watch case and the method of making said watch case.
The prior art discloses various sealed and water-tight watch cases utilizing gaskets of various materials. In particular, U.S. Pat. No. 2,495,552 to O. Schmitz, which issued on Jan. 24, 1950, discloses the utilization of various packing rings to seal the back to a case band or the case itself as well as the bezel and crystal to the case and to each other. The patent specifically discloses the use of sealing rings to effect a water-tight seal between the various case components.
U.S. Pat. No. 3,156,086 to J. Egger which issued Nov. 10, 1964, discloses the utilization of an epoxy material which is applied in the form of a liquid or paste to seal a joint between the watch caseback and bezel. The material is applied to the location, the excess epoxy wiped off and then hardened in place with the application of heat. The utilization of formed-in-place seals permit greater flexibility in the tolerance of the bezel, the case, the back and the crystal. The patent specifically refers to an epoxy material either in liquid or paste form such as a metal glue. This would provide a permanent bond which would be destroyed on disassembly of the caseback and/or crystal.
In U.S. Pat. No. 2,187,863 to E. Morf, which issued Jan. 23, 1940, the invention involves a watch crystal for watertight watches wherein the crystal edges comprise a permanently soft synthetic resin material. The soft crystal edges are pressed between the bezel and case band to form a watertight joint.
The present invention, however, provides a sealed watch case wherein a bead of adherent resilient compressible elastomeric polymer or copolymer becomes an integral part of the watch case components. If the bead is laid down on the crystal seat, disassembly of the crystal for replacement due to scratches, cracking or breakage of the crystal does not impair the effectiveness of the bead when a new crystal is inserted. Furthermore, if the bead is laid down on the bezel in the caseback area or directly onto the caseback, it too becomes an integral part of either watch case component. Disassembly of the case back for any reason such as movement or repair does not affect the bead's functionality. Interchangeability of individual components is possible, i.e., the original assembly of crystal, watch case and caseback can be changed with components of identical configuration without losing effectiveness of the original seal.